RESUMEN
Background: Instability is a common cause of (total knee arthroplasty) TKA failure, which can be prevented by achieving proper gap balance during surgery. There is no consensus on the ideal gap balance in TKA, and different alignment philosophies result in varying soft-tissue tightness. Traditional TKA aims for symmetric compartment balance, while kinematic alignment (KA) restores anatomy and accepts asymmetric flexion gaps. This study evaluated the impact of these philosophies on the flexion gap balance and clinical outcomes. Methods: A retrospective review of 167 patients who received true or restricted KA robotic-assisted TKA with at least one year of follow-up was conducted. The groups were based on intraoperative flexion gap differences: symmetric (0-1 mm) (n = 94) and asymmetric (2-5 mm) (n = 73). Results: Preoperative demographics and postoperative clinical and functional scores were compared. Both groups were similar in demographics and preoperative scores. True KA alignment was more likely to result in an asymmetric flexion gap, while restricted KA produced symmetric gaps. Conclusions: The study found no adverse effects from the physiological asymmetric flexion gap, with clinical and functional outcomes comparable to symmetric gaps. A 5 mm difference between the medial and lateral gap width did not negatively impact the outcomes. True KA more frequently results in a physiological asymmetric flexion gap.
RESUMEN
The aims of this study were to evaluate the outcomes of patients undergoing kinematic alignment (KA) robot-assisted (RA) total knee arthroplasty (TKA) with and without preoperative fixed flexion contracture (FFC) and address whether additional resection of the proximal tibia is required to address FFC. A retrospective review from 147 consecutive patients who received an RA-TKA with KA and a minimum one-year follow-up was performed. Preop and postop clinical and surgical data were collected. Groups were set based on preoperative extension deficits: group 1 (0-4°) (n = 64), group 2 (5-10°) (n = 64) and group 3 (>11°) (n = 27). There were no differences in patient demographics among the three groups. In group 3, the mean tibia resection was 0.85 mm thicker than group 1 (p < 0.05) and the preoperative extension deficit was improved from -17.22° (SD 3.49) preop to -2.41° (SD 4.47) postop (p < 0.05). Our results demonstrate that FFC can successfully be addressed in the RA-TKA with KA and rKA and that no additional femoral bone resection is needed to achieve full extension in patients with preoperative FFC when compared with patients without FFC. Only a slight increase in the amount of tibial resection was observed, but this was less than one millimetre.
RESUMEN
A shallow sulcus characterizes trochlear dysplasia (TD) of the femoral trochlea, which can lead to chronic pain or instability of the patellofemoral joint. Breech presentation at birth has been identified as a risk factor for developing this condition, which an ultrasound can identify early. Early treatment could be considered at this stage, given the potential for remodelling in these skeletally immature patients. Newborns with breech presentation at birth who meet the inclusion criteria will be enrolled and randomised in equal proportions between treatment with the Pavlik harness and observation. The primary objective is to determine the difference in the means of the sulcus angle between the two treatment arms at two months. Ours is the first study protocol to evaluate an early non-invasive treatment for TD in the newborn with breech presentation at birth using a Pavlik harness. We hypothesised that trochlear dysplasia could be reverted when identified and treated early in life with a simple harness, as it is done with developmental dysplasia of the hip.